Searchlight director



, June 4, 1935. P. R. BAssETT -Er Al. 2,003,661

SEARCHLIGHT DIRECTOR Filed may 16, '1952 4 sneet-sneet 1 *June 4, 1935. Y P. R. BAssET'r YEl.' AL 2,003,661

sEARcHLIGHT DIRECTOR Filed may 16, 1932 '4 sheets-sheet 2 o /6 57` 58 30 5l l /4 46l- I f5. 52 28 @Qu A June 4, 1935. P. R. BAssETIT. ET AL SEARCHLIGHT DIRECTOR Filed May 1e, 1932 4 sheets-sheet s vlvlvllllllllllll lllllllH u f EN June 4, 1935- P. R. BAssETT r-:TL 2,003,661

SEARCHLIGHT DIRECTOR '4 Sheets-Sheet 4 vF'ilei May 16, 1932l FRANK Hoz/5E Patented' .im 4,v 193s UNITED -srATEs vPATi-IsVr oFFlcE Preston B.. Bassett, Rockville Centre, and Frank R. House, Baldwin Harbor, N. Y., assignors to Sperry Gyroscope Company, Inc., Brooklyn,

4`N. Y., a corporation of New York Application May 1s, 1932, serai Nogeusss- 2o claims: (ci. 24o-1.2)v i This invention relatestoapparatus for locating and illuminating aircraft at `night so that antiaircraftgun ilre may be directed thereon. The

present practice is to'employ a sound locating device, such as a binaural sound locator, or other' non-optical system of locating the target blind and ,to transmit therefrom to a searchlight the location of the target, after applying certain corrections. Such a system is outlined in the prior application of Frank R. House, one of the joint inventors hereto, now Patent No. 1,976,727, dated October y16, 1934, for Sound locators and computers for aircraft. With such a system, a continuous series of datum pointsor predicted positions is determined from the direction of the incoming sound with proper corrections applied thereto. It is at this point in the sky that the searchlight beam is directed. However, as there are always certain `errors in listening and in the prediction of the target position, it has been found necessary' to move the searchlight about the datum positions, so as to search around these po- 4 sitions until the target is found..

Our invention relates particularly to an im-v provement in the method of searching through a denite limited area around this datum position in a systematic manner so as to scan every point Within this area and to make certain that this vcomplete area will beprogressively illuminated within a very short interval so as to leave no blind spots in which the plane could be without being ilicked by the bram. According to our invention we interpose in the automatic distant` control of the searchlight from the comparator a mechanism senil-automatic in character and preferably manually controlled, which causes the searchlight to scan a complete area about the datum position. The area scanned is chosen as the outside limits of error in transmitting the pr-dicted position so that it amounts to a cone of only a few degrees in azimuth and elevation.

-searchlight operator at the binocular observation or control station.

Another object of the invention is to provide at. the comparator or control device, binoculars or a sighting telescope which is kept trained auto-v matically at the same point inthe heavens that the searchlight beam is directed so that the observer-operator at the comparator may always have his sight directed in the same direction as the searchlightbeam which. he-is observing and, thereIore. be-ab1e to pick up instantly the target when ilicked'by the beam.

Referring to the :drawings showing several forms our invention may assume:

Fig. 1 is a schematic viewv showing three principal elements ot a sound locator searchllght battary, namely, thevsound locator, the comparator and the se'archlight.4

Fig. `2 is a. schematic view showing the preferred form of mechanism for a scanning operation. s

Fig. 3. is a sectional detail of the mechanism whereby the beam is caused to search in an outwardly spiral path from the datum position.,

Fig. 4V shows the resulting spiral movement of a searchlight beam.

Fig. 5 is a diagrammatic view of the mechanism within the comparator which supplementsv the showing in Fig. 2.

Fig. 6 is a diagrammatic view of a modied form of the invention. Y

Fig. I is a diagram showing the path of movement of the searchlight beam resulting from the form of the invention shown in' Fig. 6.

The sound locator is shown generally at L in Figs. 1 and 2 and preferably consists of a pair of horns A and Bspaced apart in azimuth and another pair of horns C Vand D spaced apart in elevation. -There is one operator for each pair of horns, the azimuth operator listening through the ear pieces in the helmet E and the elevation operator listening throughthe ear pieces in the helmetF. All the hornsturn together but the azimuth operator turns them in azimuth through handle G, and the elevation operator similarly controls the horns in elevation through the handle H. 'I'he exact positions oi' the horns in azimuthand elevation are not transmitted, however, but the coryrections (more particularly described in the aforesaid prior application) are rst introduced through the differentials 6 in lazimuth and '1 in elevation, the Acomputing, mechanism being 1ocated in the base 8 of the sound locator.

From the correction mechanism 8, the azimuth and elevationV angles are transmitted `through transmitter 80 and 8| and cable 9 to the comparator I Il the upper portion of'which is rotatably mounted on its tripod base. 'l'his device forms a means by which position of the searchilghts is controlled and is usually located at some distance from the searchlight in orderto obtain better vision. If desired, the searchlight angles couidwbe automatically transmitted from the sound locator as indicated in Fig. 6, but we have shown in Figs. 1 to 5 the searchlight as controlled throug a manual follow-the-pointer system, the azimut position of the sound locator being transmitted to a dial II in the comparator and the elevation to a dial I2. It is, therefore, the duty of the operator of the handwheel I3 to match the outer pointer I4 with the pointer on the dial II and it is the duty of the operator of the elevation handwheel I5 to match the outer pointer I6 with the pointer on dial I2. Dials I I and I2 are controlled respectively from suitable repeater motors I1 and I8 actuated from transmitters 80 and 8| in the base of the sound locator I.

Referring first to Fig. 2, Vthere is shown interposed between the handle I3 and the dial I4 one or more differentials and 2|. Through the center arm of differential 26 is introduced one component of the scanning or searching motion. As shown, the center arm 22 is provided with a spur gear meshing with an elongated pinion 23 on shaft 24. On said shaft is a pinion 25 meshing with rack teeth 26 on a rack bar 21. As shown in Fig. 2, the pinion 25 and the rack teeth are in a plane at right angles to the plane of shaft 24 in order to show these parts in one ngure, but it will be understood that the plane of the pinion 25 is readily perpendicular to the paper as is the pinion 28 on the same shaft. A similar pair of differentials 20 and 2|' is provided between the elevation handwheel I5 and the elevation dial I6. Likewise a similar shaft 24 is provided, having a pinion 23' meshing with spur gear 22 on the planetary arm of the differential. Shaft 24' is likewise provided with a pinion 25 meshing with rack teeth 26' on a second bar 29 pivoted at its upper end on a common pivot pin 36 with the bar 21. From the center of the two pinions 25 and 25' to the center of the pivot pin 30 constitutes a right angle when the pin is .in its central or inoperative position.

Pivot pin 30 is shown mounted on a block 3I which is slidably but non-rotatably mounted on a shaft 32. Said shaft has an endless double spiral groove 33 therein into which `projects a pin 34 from the interior of the block 3|. Rotation of the shaft 32 will, therefore, cause the block 3| to travel back and forth along the shaft. Shaft 32 is journalled adjacent its ends in a bracket 35 .which is secured to a shaft 36 at right angles to the shaft 32 and positioned to one side of the center of the shaft 32. Rotation of the shaft 36 by handwheel 44 will, therefore, revolve the bracket about the center thereof. On shaft 32 is also secured a bevel pinion 31 meshing with a second bevel gear 38 loosely mounted on shaft 36. If gear 38, therefore, is held stationary (as by lug 38') and the bracket 35 revolved, it will readily be seen that the block 3I and its stub shaft 30 will not only be revolved about shaft 36 as a center but will also reciprocate along the shaft 32 by the rolling of the bevel gear' 31 around bevel gear 38. If block 3| is started with pin 30 concentric with shaft 36, the revolving of the shaft 36 will cause the pin 30 to execute first an outward spiral and then an inward spiral. In order' that the operator may be informed when shaft 36 and pin 30 are concentric, we have shown a pinion 40 on shaft 36 meshing with a large gear 4I, the gear ratio being such that one turn of gear 4I equals one complete in and out spiral of pin 38. A pin 42 is shown on the gear designed to snap past a spring click 42 when the shafts 36 and 30 are concentric, so that the operator may know when the beam is in the datum position.

'Ihe spiral movements of the pin 30 are resolved into azimuth and elevation components by right angle bars 21, 29 pivoted thereon, the

reciprocating movements of said bars being transmitted to pinions 25, 25' respectively and thus through shaft 24, 24' to the differentials 26 and 20'. The third arm of said differential, therefore, turns the output shaft 43 through an angle `equal to the algebraic sum of the movements of the handwheel I3 and the scanning mechanism. Obviously automatic means may be used to turn shafts I3 and 36, if desired. Transmitter 45, therefore, on shaft 43 transmits both the datum and scanning movements of the searchlight in azimuth while the corresponding transmitter 45' on the shaft 43 transmits the elevation datum and the scanning movements. The spiral convolutions are made suiciently close so that no blind area is left within the normal range of the searchlight. Obviously the rotation of the hand wheel 44 may be arrested at any time so that the searching action may be stopped thev moment the target is flicked. Also, by having the search made in a definite pattern, the operation may be reversed at any time so that the observer may turn the beam backwardly if desired to pick up the target if he passed it at first.

It is.not desirable, however, that the scanning movements should reach the follow-the-pointer dials II and I2 as these would disturb` the proper operation of the system. Therefore, a second diierential 2I (and 2I) is interposed in which the planetary arm 46, (46') is operated from the shaft 24, (24') so as to take out the scanning movements after they .have been introduced. Such differentials, however, do not interfere with the transmitters 45 and 45'. If it is desired to cut out the scanning mechanism as when synchronizing the searchlight and comparator, the operator may pull out shafts 24 and 24' by knobs 41, 41' thus disconnecting pinions 25 and 25 and bringing the pinions 23, 23 into engagement with stationary gear 48.

Fig. 5 shows in a somewhat different manner the same mechanism shown in Fig. 2, certain parts, however, being omitted and additional features shown, like parts having the same reference characters. In this figure there are shown additional handwheels I3 and I5' which are operated bythe spotter or observer, while the handwheels I3 and I5 are operated solely to match the pointers II, I4 and I2, I6. Handwheel I3 is shown as mounted on a long shaft 53 to which is pinned a double face clutch member 52. Said shaft 53 is also shown as extending loosely through the hub of the handwheel I3 and is provided at its upper end with a knob 54. When handwheel I3 is rotated with the clutch in the position shown in Fig, 5, gear 56 which is provided with a complementary clutch face is likewise rotated, thus rotating the gear 5I and. one arm ofthe differential 20. As before, the scanning movement is introduced through a shaft 24 and pinion 23 and the resultant movements transmitted through friction clutch to the shaft 56, on which are mounted the transmitter 45 and a gear 51. The latter drives a gear 58 on a sleeve 59 which is slidably but non-rotatably mounted on a long inner sleeve 60. Sleeve 59 is yieldingly held in the position shown in full lines in Fig. 5 by spring 60". If, however, the knob 54 be pushed inwardly, clutch 52 is disengaged from gear 50 and brought into engagement with the clutch face 6I on the upper end of the sleeve i59, also pushing the sleeve 59 downwardly into dotted line position in Fig. 5. This movement rst disconnects the handle Il from the control of the transmitter and also disconnects the gears 51 and 58 so that the handwheel I! no longer has control of the pointer I4. Rotation of the handwheel I3' under these circumstances will directly drive the gear 59 through the sleeve 62 thus driving the. transmitter .45 therefrom without turning the pointer I4 or the binoculars connected therewith as hereinafter described. This control is mainly used when synchronizing the searchlight and comparator 'or the sound locator and comparator. The elevation control is similar through the handvvheels I5 and I5', corresponding parts being shown-by primed reference characters. Theoperation of this portion of the invention is that the operators of the handwheels Il and I5 control the searchlight beam by,matchlng pointers until the targetfis-sighted.' the vobserver at this time rotating handwhee'lf 44 to operate the scanning mechanism. When the target is sighted through the binoculars, the observer re-v leases the handwheel 44 and assumes direct control through handwheels I3 and I I' preferably without pushing the knobs 54 and 54' inwardly. Buttons 41, 41'. may be pulled upwardly at the same time so that the scanning device is also rendered inoperative, although this is unnecessary as handwheel 44 is idle. The searchlight is controlled from the azimuth and elevation trans-v mitters 45 and 45' vwhich turn the searchlight through repeater motors 91 and 91', which may be employed either with or without power militiplying motors 98 (Fig. l).

We also prefer to mount the binoculars on the comparator in such a manner that they are maintained in the direction of the searchlight.

beam." For this purpose the binocular 95 is mounted directly on the comparator I0 and since the comparator rotates and oscillates in azimuth as the handwheels I3 and I4 are turned, the proper position in azimuth is maintained by the binoculars. necting the sleeve 69 to the large gear 96 which carries the upper or rotatable portion of the comparator, gear 66 being shown as rotated from the sleeve throughbevel gear 81, shaft 6 9 and bevel gear 69. For movements in elevation the binoculars are-shown as mounted-on a linkage system pivoted tothe block 9 9'. There are shown two parallel links 692110 pivoted on the-block and connected by a cross link 1I. The binoculars proper are iixed to the upper lever 89' so that when the linkage is revolved or oscillated in counter-clockwise direction in Fig. 1, the binocular is tilted upwardly as shown' in dotted lines. 'Ihe tilting movement of the binoculars is shown as governed by the rotation of 'the sleeve 90'. As shown, the' sleeve 60' isconnected through bevel gear 10', 12 to flexible shaft 13 on which is a worm 14 meshing with a worm sector 15. l'll'he latter is mounted on the shaft 19 vof the lever 10 so that the lever rocks with the worm. Therefora-the binoculars automatically follow not only the main movements of the searchlight but also the seanningm'ovements aslong as the handle-44 is rotated and buttons 41 and 41' remain down.-

This is highly desirable as the observeris then unconscious that either the searchlight beam or the binoculars are oscillating since they are kept directly together at all timesthe binocular being directed at the same point in the heavens as the searchlight.

In Fig. 6 both a modiiiedform of the scanning vpower motor 91.

This is represented in Fig. 5 by conarea around said location device and searchlight control is shown. In this'gure the azimuth and elevation transmitters at the sound locator are again lshown at I9 and 9|. In this case instead of showing a follow-the-pointer system, we have shown `a complete automatic follow-upsystemv in vwhich the searchlight is automatically driven from the sound locator without human follow-upa" For; this purpose the repeater motor I1 is shown as turning one portion l2 of a reversing controller,-

i. e., the revolving trolleys or brushes 'for-the reversing contactar segment 83 (both shown dlagrammatically). The latter is mounted on a shaft u driven from a. wormwheei alsv turned from a worm 99 on the shaft of a reversible The power motor, therefore.y drives the contacting segment into coincidencev with the position oi' the trolleys. The power motor .also operates to position the searchlight in azimuth. For this purpose it is shown as driving through worm gearing 98 one arm of a differential gear train 89.

of the searchlight through the. pinion 94 whichl turns through shaft 95 the transmitter 96. Said transmitter operates the powerful repeater motor 91 at the searchlight for turning the same. The scanning movement may be either power driven through a motor 98 or controlled by hand through a handwheel99, or both. In elevation the control may be similar except that in this case the scanning movement is such as to cause the searchlight beam to scan the desired iield of movement by a series of advancing step-bystep or receding movements, the iinal effect being to move the beam as indicated in Fig'. 7. For this purpose there is mounted on the shaft of the gear 9i' driven from motor 98 or handwheel 99 an eccentric cam |90 having/radially laid-out steps or teeth to give the required movements to the cam lever IIII pivoted at |02. Said lever rocks the third arm of the differential 99', and the combined movement turns elevation transmitter '99', which operates transmitterV 91 through cable |02'.

In accordance with. the provisions of the patent statutes, we have herein described the principle and operation of our invention, together with the apparatus which we now consider to represent the best embodiment thereof, but we desire `omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described our invention, what we claim and desire to secure by Letters Patent is:

1. In a preliminary positioning system for searchlights, means for approximately locating a targetby non-optical means,l remote control Y means for directing the searchlight therefrom, and means for introducing at will within said di- Through the oppo-V sitearm of 'the same is introduced the scanning recting means an additional to and fro motion.

to cause said searchlight to scan apredetermined l until the target is' picked up.

2. In a preliminary positioning system i'or antipositioning the searclilight in azimuth and elevation including means for transmitting the anticipated position of the searchlight in azimuth and elevation and means ior introducing into said,

last named means an oscillatory motion to cause said searchlight to systematically `scan a predetermined area around said anticipated position to pick up the target.

3. In a combined blind--searchlight system fo locating aerial targets at night, the combination with a non-optical locator and searchlight, of means controlled from said locator and remote from the searchlight for directing the latter at the target as indicated by said locator, a sight at said means, and means connecting said sight and iirst named means to maintain said sight. pointed at the target.

4. In a remote control for searchlights, means for positioning the searchlight in the anticipated position in azimuth and elevation, a sight for following the target, means for causing said searchlight to scan a predetermined area around said position to flick the target, and means for causing said sight to follow all movements of the searchlight.

5. In a sound locator system for initially positioning searchlights, the combination with a sound locator, control station and searchlight, of means actuated from the control station for maintaining the searchlight pointed at the target as indicated by the sound locator and means at the control station for superimposing. on such motion a limited systematic scanning motion to cause the searchlight to scan an area. around the indicated position at least equal to the ordinary limits of error of the sound locator.

6. In a sound locator comparator system for positioning searchlights, the combination with a sound locator, comparator and searchlight, means actuated by the sound locator for actuating lndicators at the comparator, means at the comparator for introducing a limited scanning movement, means for transmitting the combined indica ted and scanning movements, and means for preventing lthe scanning movements from aiecting said indicators. y

7. In a sound locator comparator system for positioning searchlights, the combination with a sound locator, comparator and searchlight, means actuated by the sound locator for actuating relative position indicators at the comparator, a plurality of manual means at the comparator for governing the searchlight, certain of said means being operated by match-the-pointer operators to maintain the proper relation between. said relative position indicators, another of said means being initially operated by the target observer to superimpose a scanning movement, and another of said means for operation bythe observer after sound locator, comparator and searchlight, means actuated by the sound locator for actuating relative position indicators at the comparator, means at the comparator for introducing a limited scanning movement, a plurality of manual means at the comparator .for governing the searchlight, certain of said means being operated by matchaooaeci-- the-pointer operators to maintain the proper re-v lation between said relative position indicators and others of said means being operated by target observer, and means whereby said observer may cut out said scanning movement and transfer the 5 searchlight control from said pointer operators to the observer when the target is once sighted.

9. In a remote control for searchlights, means for'positioning the searchlight in a predicted position in elevation and azimuth including means l0 for transmitting said predicted positionI inazimuth, means for transmitting said predicted position in elevation, and means for introducing into each of said means simultaneously a continuously increasing to and fro motion whereby-said search- 15 light is caused to move in an outwardly expanding spiral around said predicted position oi' sumciently close convolutions to leave no blind areawithin the normal range of the searchlight.

10. In a remote control for searchlights, means 2 at the control station for setting up the indicated azimuthal position of the searchlight beam, means for setting up the elevation angle. and means for introducing at the control station a supplementary scanning movement in the searchlight 25 comprising a member, means for revolving said member in a spiral path, means for resolving the movements of said member into right angular components, and azimuth and elevation transmitting means each actuated jointly by said azimuth and elevation positioning means and the corresponding components of said scanning means.-

1 1. In a remote `control for anti-aircraft searchlights, means for. indicating the approximate position oi' the aircraft, primary transmitting means 35 for directing said searchlight in both azimuth and elevation toward said position. and manual means operable at will for introducing a comparatively rapid to and fro component in one of-said vtransmitting means and a. slower motion in the 40 other of said means, whereby the beam is caused to search in a progressive zigzag fashion.

12. In a remote control for searchlights, means for transmitting the azimuthal position to the searchlight, means Afor transmitting the eleva.-

of'said transmitting means about said position, 50.'

and means for causing a step-by-step progressive movement in said other transmitting means.

13. In a remote control for searchlights, means for transmitting the azimuthal position to thel searchlight, lmeans for "tsansn'iitting the'eleva- 55 tion angle, and means for introducing a supplementary scanning movement in vthe searchlight comprising a member, means for revolving said member in a spiral path, means for resolving the movements of said member in two right angular components, means for introducing said components into sai'd, azimuth and elevation transmitting means respectively. and means for indicating when saidy member is at lthe, center or origin of its spiral.

14- In a combined blind-searchlight system for locating aerial targets at night, the combination with a non-optical locator and searchlight, of means controlled from said locator and remote from the-searchlight for directing the latter' at the target as indicated by said locator, asight at said means. means connecting said sight and first-named means to maintain said sight pointed at the target, and means whereby the sight obrver may assmne control of the searchlight upon the target being icked. j 15. In a remote control for searchlights, means for positioning the searchlight in the anticipated position in azimuth and elevation, a sight for following the target, means for causing said searchlight to scan a predetermined area around said position to flick the target, means for causing said sight to follow all movements of the searchlight, and means whereby the sight observer may assume control of the searchlight upon the target being flicked.

16. In a non-opticallocator comparator/system for positioning searchlights, the combination with a non-optical locator, comparator and searchlight, means actuated by the locator for actuating indicators at the comparator, means at the comparator for introducing a limited scanning movement, and means for transmitting the combined indicated and scanning movements.

V 17. In a sound locator comparator system for positioning searchlights, the combination with a `somidlocator, comparator and searchlight, means actuated by the sound locator for actuating indicators at'the comparator, means at the comparator for introducing a limited scanning movement.

means for transmitting the combined indicated said trame is pivoted for turning in azimuth,

handwheels for moving said sight in azimuth' taining/the sight 'and beam pointed at a common point in the heavens.

19. In a remote control system for searchlights, a sight, a frame on which the same is mounted for movements in elevation, a support in which said frame is pivoted for turning in azimuth, handwheels for moving said sight in azimuth and elevation both mounted for revolution in azimuth with said frame, transmitters actuated by said handwheels, and repeater motors at the searchlight actuated from said transmitters for maintaining the sight and beam pointed at a common point in the heavens and whereby the operatorobserver always faces toward the searchlight beam.

20. In a non-optical locator system for initially positioning searchlights, the combination with a non-optical locator, control device and searchlight, of means actuated from the control device for maintaining the searchlight pointed at the target as indicated by said locator, and means at the control device for superimposing on said motion a limited systematic scanning motion to cause the searchlight to scan an area around the indicated position, said means permitting said scanning motion to be stopped or reversed from the control devic'e at will.

PRESTON R. BASSE'I'I. FRANK R. HOUSE. 

